From mboxrd@z Thu Jan 1 00:00:00 1970 From: yang.shi@linaro.org (Shi, Yang) Date: Wed, 20 Apr 2016 16:01:39 -0700 Subject: [BUG] set_pte_at: racy dirty state clearing warning Message-ID: <57180A53.3000207@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Will and Catalin, When I enable memory comact via # echo 1 > /proc/sys/vm/compact_memory I got the below WARNING: set_pte_at: racy dirty state clearing: 0x0068000099371bd3 -> 0x0068000099371fd3 ------------[ cut here ]------------ WARNING: CPU: 5 PID: 294 at ./arch/arm64/include/asm/pgtable.h:227 ptep_set_access_flags+0x138/0x1b8 Modules linked in: CPU: 5 PID: 294 Comm: systemd-journal Not tainted 4.6.0-rc3-next-20160414 #13 Hardware name: Freescale Layerscape 2085a RDB Board (DT) task: ffff80001e4f8080 ti: ffff80001e8b4000 task.ti: ffff80001e8b4000 PC is at ptep_set_access_flags+0x138/0x1b8 LR is at ptep_set_access_flags+0x138/0x1b8 pc : [] lr : [] pstate: 20000145 sp : ffff80001e8b7bc0 x29: ffff80001e8b7bc0 x28: ffff80001e843ac8 x27: 0000000000000040 x26: ffff80001e9ae0d8 x25: ffff200009901000 x24: ffff80001f32a938 x23: 0000000000000001 x22: ffff80001e9ae088 x21: 0000ffff7eb59000 x20: ffff80001e843ac8 x19: 0068000099371fd3 x18: fffffffffffffe09 x17: 0000ffff7ea48c88 x16: 0000aaaacb5afb20 x15: 003b9aca00000000 x14: 307830203e2d2033 x13: 6462313733393930 x12: 3030303836303078 x11: 30203a676e697261 x10: 656c632065746174 x9 : 7320797472696420 x8 : 79636172203a7461 x7 : 5f6574705f746573 x6 : ffff200008300ab8 x5 : 0000000000000003 x4 : 0000000000000000 x3 : 0000000000000003 x2 : ffff100003d16f64 x1 : dfff200000000000 x0 : 000000000000004f ---[ end trace d75cd9bb88364c80 ]--- Call trace: Exception stack(0xffff80001e8b79a0 to 0xffff80001e8b7ac0) 79a0: 0068000099371fd3 ffff80001e843ac8 ffff80001e8b7bc0 ffff200008497b70 79c0: 0000000020000145 000000000000003d ffff200009901000 ffff200008301558 79e0: 0000000041b58ab3 ffff2000096870d0 ffff200008200668 ffff2000092b0e40 7a00: 0000000000000001 ffff80001f32a938 ffff200009901000 ffff80001e9ae0d8 7a20: 0000000000000040 ffff80001e843ac8 ffff200009901000 ffff80001e9ae0d8 7a40: ffff20000a9dcf60 0000000000000000 000000000a6d9320 ffff200000000000 7a60: ffff80001e8b7bc0 ffff80001e8b7bc0 ffff80001e8b7b80 00000000ffffffc8 7a80: ffff80001e8b7ad0 ffff200008415418 ffff80001e8b4000 1ffff00003d16f64 7aa0: 000000000000004f dfff200000000000 ffff100003d16f64 0000000000000003 [] ptep_set_access_flags+0x138/0x1b8 [] handle_mm_fault+0xa24/0xfa0 [] do_page_fault+0x3d4/0x4c0 [] do_mem_abort+0xac/0x140 My kernel has ARM64_HW_AFDBM enabled, but LS2085 is not ARMv8.1. The code shows it just check if ARM64_HW_AFDBM is enabled or not, but doesn't check if the CPU really has such capability. So, it might be better to have the capability checked runtime? Thanks, Yang